Hi, I have to build a small soil moisture monitor for 4 type of soil at the same time (the test was made on the same soil/same moisture). I build sensor and code a sketch (based on GardenBot) to read 4 of them from Arduino Uno. I've got some weird read value. In my test, i can see that the DigitalPin 5 and 10 cannot provide enough power for the sensor?? Someone know why? I also try to use AnalogPin 5 to 2 and only pin 2 and 3 give good reading.... I change the ATMEGA328p because i have spare and nothing change. I post the last sketch revision i made. In this sketch i can have good reading from sensor #2, #3 and #4 but the sensor #1 give me random number ranging from 400 to 800. I also post a picture to show how the sensor is made. For the 57-100K resistor i put 100K on all sensor. Help please!!

Ok ... i change the analogPin definition and it seem to work in water. When i remove it and let the sensor in the air sensor #3 and #4 give me nearly 1024 that's ok but #1 and #2 give me random number between 600 and 800... ... i use pin 4, pin 2, pin 1 and pin 0. I really don't understand why analogPin works all fine but in this sketch some AnalogPin and DigitalPin, when they are used, give me error (DigitalPin= Not enough current, AnalogPin= Bad read value) ....